I discovered (by watching another customer) that a certain kind of very expensive Scottish smoked salmon was 4 pence more expensive than the price listed on the shelf. The supermarket (Tesco) also has a large sign stating that if the price was wrong on any item, they would both give you the item for free and the money it costs.

I promptly went and loaded up a cart with nothing but smoked salmon.

It took 42 minutes of arguing with different store managers and pointing to the sign, but I managed to eat for free that week and even had enough to pay my electricity bill.

The reason I don’t feel bad is that particular store very, very often charged the customers more than the listed price and no one ever seemed to catch them.

I went in three months later, and the same salmon still rang up at 4p more than it was listed at.